What does it do?
It brings enhanced functionality to SciTE4AutoHotkey, including:DebugVars
A really nice little variable browser that allows you to explore variables and objects, and stays expanded as you step through code.
To open it, once debugging, click the icon under the mouse cursor in the screenshot above
AHK_H and AHK_L compatible.

Breakpoints in included files
If you place a breakpoint in an included file, then start debugging the main script, the breakpoint will now be hit.

CygWin
When installing CygWin, at the stage when it pops up the packages, you need to add the "patch" package (Select "Full" from the dropdown and search for "patch"). If you miss it, just re-run the installer

Extract the contents of scite360.tgz to <GithubFolder>
You may need to extract twice - the first time should yield scite360.tar, then extract again
<GithubFolder> should now contain the following folders:
installer
scintilla
scipatches
scite
source

Open a Cygwin prompt to <GithubFolder>\source

Execute patch -p1 < scipatches/S4AHK.patch

Double-click <GithubFolder>\SciTE4AutoHotkey.sln to open the project in Visual Studio

At the top of the screen, make sure the two dropdowns are set to Release and Win32

Select Build -> Build Solution

Copy SciTE.exe and SciLexer.dll from <GithubFolder>\bin\debug\x86 to <GithubFolder>\source

Take a copy of the latest 32-bit Unicode AutoHotkey.exe, rename it InternalAHK.exe and place it in <GithubFolder>\source

The contents of <GithubFolder>\source is now a patch, you can copy the contents of this folder over an existing Scite4Autohotkey install to update it.

Thank you, EvilC - and of course Fincs and Lexikos - for putting this together. Seems to work fine and will surely be useful for debugging! I always wanted to look into the abilities of the DebugVars script... and Scite4AHK I already use. So, that's perfect!

This is great set of added functionality as I'm keep all my classes in one ugly file at the moment, just because of the breakpoint issue this addresses. However, I've seen an odd issue where the performance when you're debugging grinds to a halt using this version of the code.

Stepping through code on the standard 3.0.06.01 build in real-time, after this mod, often takes several seconds per F10/F11 step. Using ANSI as a platform if that matters. Happy to help provide further diagnostics if you let me know what you need

The DebugVars window tends to display a lot more information than the original variable list, and requires a proportionate number of DBGp requests. If it slows down, try minimising some object nodes. (I've not seen it quite as slow as MPD described, but it may depend on the system and the amount of information displayed.)

Being able to run DebugVars.ahk using DebugVarsGui to display a separate window with a node for each running script with real-time access to view/modify AHK v1 and AHK V2 running scripts' variables (some running elevated), while debugging an AHK V2 script using SciTE4AutoHotkey with EvilC's S4AHK patch...

Do you have multiple monitors? I have seen issues before with any script that records window location between runs.
Sometimes it just seems to glitch out - it could be due to how the address space maps out, something as subtle as switching your monitors around or which port they are plugged into might affect it
Granted though, it's not that hard to write code to detect if that value is not visible, and move it on-screen.
I didn't write any of the code though, I just packaged it.

A value of -32000 usually means the window is minimized. Do you have a hotkey that minimizes windows? I do not think there is any other way to minimize this window.

Maximized, or just sized to fill the screen? The window has no maximize button. Maximized windows are sized larger than the screen. If you maximize the window with WinMaximize, the saved size will be inappropriate for the normal non-maximized state. The script does not restore the maximized state, because you aren't supposed to be able to maximize the window.

I suspect it has to do with AHK V1 WinGetPos gets the full window dimensions, while the Gui Show, w%Width%... command ignores window caption and some other extra pixels.

If that were the case, it would happen for everyone. It works correctly for me. WinGetPos is used only to retrieve the position of the window, not the size.

I have updated Lexikos/SciTE4AutoHotkey to fix a few issues and add support for selecting stack depth. Double-clicking a stack entry will now set the 'depth' used when querying local variables, allowing the debugger to see local variables of running functions other than the current one. This requires v1.1.30+ or v2.0-a099+; earlier versions will simply return no variables if depth is non-zero. Depth reverts to zero when execution resumes.